I believe it uses the chain rule, anyway. My professor told me in class the other day that the chain rule can be used so I would prefer if there was an answer utilizing the rule, but really, anything will do. These webwork problems kill me! TIA!
I get all of that and I get that dy/dx = dy/du * du/dx and I have what you have above. I just cannot figure out how to relate the 3x^2 to x and what to do to differentiate at x. I'm trying to use all of the classic formulas of the chain rule but I have found myself quite baffled! I'm not fishing for an answer here, but maybe there's something I'm missing?
if you have
now try to work from that idea. you want to somehow write the function in terms of , and then replace the with . that is all
Okay. I think I understand now. Here's what I did now:
I rewrote the function of (7/6)x^3 as 3x^2 * (7/18)x, since I'm trying to rewrite the derivative in terms of 3x^2 so I can replace it with just x. I did that and was left with x * (7/18)x, multiplied it out to get (7/18)x^2.
But the answer is still wrong. I thought I had a pretty good grasp on this stuff, but apparently I was wrong! Am I still missing something?